Electronic percussion instrument and method of detecting percussion position

Abstract

An electronic percussion instrument and a method of detecting a percussion position are provided. The percussion position in a left-right direction is calculated by comparing an added-up value of output values of a first edge sensor with an added-up value of output values of a second edge sensor. Compared with a case where peak values of the first and second edge sensors are used, it is possible to make a great difference between an added-up value in a case where the vicinity of the first edge sensor (the second edge sensor) is percussed and an added-up value in a case where a position away from the first edge sensor (the second edge sensor) is percussed.

What is claimed is: 
     
       1. An electronic percussion instrument comprising:
 a percussion surface; 
 a first sensor, a second sensor and a third sensor that detect a vibration of percussion on the percussion surface; 
 a first calculation unit that calculates a percussion position in a first direction which is a direction of alignment of the first sensor and the second sensor on the basis of a ratio or difference between an added-up value of output values of the first sensor within a predetermined time after the percussion surface is percussed and an added-up value of output values of the second sensor within the predetermined time; 
 a first determination unit that determines presence or absence of the percussion on the percussion surface on the basis of an output value of the third sensor; 
 virtual divided regions formed on the percussion surface, being a plurality of divided regions lined up in the first direction between the first sensor and the second sensor; 
 a second determination unit that determines which of the plurality of divided regions is percussed on the basis of the percussion position in the first direction; and 
 an instruction unit that performs an instruction for generation of musical sounds that vary depending on the plurality of divided regions or an instruction for a change of qualities of the musical sounds on the basis of a determination result of the second determination unit, 
 wherein the third sensor is disposed closer to a center of the percussion surface than to the first sensor and the second sensor, 
 wherein a starting point of the predetermined time is set to a point in time before a point in time when the first determination unit determines the presence of the percussion on the percussion surface, and 
 the electronic percussion instrument is configured to capable of switching between the following two modes: 
 a first mode in which the divided regions are formed in at least three regions of a first region formed at a center of the percussion surface, a second region formed closer to the first sensor than to the first region, and a third region formed closer to the second sensor than to the first region; and 
 a second mode in which the divided regions are formed in at least two regions of a fourth region formed on the first sensor side with the center of the percussion surface as a boundary and a fifth region formed on the second sensor side with the center of the percussion surface as a boundary, 
 wherein the first mode is set in a case where an interval of the percussion on the percussion surface is equal to or greater than a predetermined value, and the second mode is set in a case where the interval of percussion is less than the predetermined value. 
 
     
     
       2. The electronic percussion instrument according to  claim 1 , further comprising a second calculation unit that calculates a percussion position in a second direction orthogonal to the first direction on the basis of a length of an initial half wave detected by the third sensor after the first determination unit determines the presence of the percussion on the percussion surface. 
     
     
       3. The electronic percussion instrument according to  claim 2 , wherein the second calculation unit corrects and calculates the percussion position in the second direction on the basis of the percussion position in the first direction. 
     
     
       4. The electronic percussion instrument according to  claim 3 , wherein the second calculation unit calculates a provisional value of the percussion position in the second direction on the basis of the length of the initial half wave, and calculates the percussion position in the second direction by subtracting a value based on the percussion position in the first direction from the provisional value. 
     
     
       5. The electronic percussion instrument according to  claim 1 , further comprising:
 a ring buffer in which the output values of the first sensor and the second sensor are stored for an amount of a predetermined storage time so as to be updated in a time-series manner; and 
 an added-up value calculation unit that calculates a sum of the output values of the first sensor and a sum of the output values of the second sensor which are stored in the ring buffer each time the ring buffer is updated, 
 wherein the predetermined storage time and the predetermined time are set to have the same length. 
 
     
     
       6. The electronic percussion instrument according to  claim 1 , wherein a formation mode for the divided regions is changed on the basis of a change in the interval of the percussion on the percussion surface. 
     
     
       7. The electronic percussion instrument according to  claim 1 , wherein the first calculation unit calculates a coordinate of the percussion position in the first direction on the basis of a magnitude of a ratio or difference between the added-up value of the output values of the first sensor and the added-up value of the output values of the second sensor. 
     
     
       8. An electronic percussion instrument comprising:
 a percussion surface; 
 a first sensor and a second sensor that detect a vibration of percussion on the percussion surface, and a third sensor disposed closer to a center of the percussion surface than to the first sensor and the second sensor; 
 a first calculation unit that calculates a percussion position in a first direction which is a direction of alignment of the first sensor and the second sensor on the basis of a ratio or difference between an added-up value of output values of the first sensor within a predetermined time after the percussion surface is percussed and an added-up value of output values of the second sensor within the predetermined time; 
 a first determination unit that determines presence or absence of the percussion on the percussion surface on the basis of an output value of the third sensor, wherein a starting point of the predetermined time is set to a point in time before a point in time when the first determination unit determines the presence of the percussion on the percussion surface; and 
 a second calculation unit that calculates a percussion position in a second direction orthogonal to the first direction on the basis of a length of an initial half wave detected by the third sensor after the first determination unit determines the presence of the percussion on the percussion surface; 
 virtual divided regions formed on the percussion surface, being a plurality of divided regions lined up in the first direction between the first sensor and the second sensor; 
 a second determination unit that determines which of the plurality of divided regions is percussed on the basis of the percussion position in the first direction; and 
 an instruction unit that performs an instruction for generation of musical sounds that vary depending on the plurality of divided regions or an instruction for a change of qualities of the musical sounds on the basis of a determination result of the second determination unit, 
 wherein the electronic percussion instrument is configured to be capable of switching between the following two modes: 
 a first mode in which the divided regions are formed in at least three regions of a first region formed at a center of the percussion surface, a second region formed closer to the first sensor than to the first region, and a third region formed closer to the second sensor than to the first region; and 
 a second mode in which the divided regions are formed in at least two regions of a fourth region formed on the first sensor side with the center of the percussion surface as a boundary and a fifth region formed on the second sensor side with the center of the percussion surface as a boundary, 
 wherein the first mode is set in a case where an interval of the percussion on the percussion surface is equal to or greater than a predetermined value, and the second mode is set in a case where the interval of percussion is less than the predetermined value. 
 
     
     
       9. The electronic percussion instrument according to  claim 8 , wherein the second calculation unit corrects and calculates the percussion position in the second direction on the basis of the percussion position in the first direction. 
     
     
       10. The electronic percussion instrument according to  claim 9 , wherein the second calculation unit calculates a provisional value of the percussion position in the second direction on the basis of the length of the initial half wave, and calculates the percussion position in the second direction by subtracting a value based on the percussion position in the first direction from the provisional value. 
     
     
       11. The electronic percussion instrument according to  claim 9 , further comprising:
 a ring buffer in which the output values of the first sensor and the second sensor are stored for an amount of a predetermined storage time so as to be updated in a time-series manner; and 
 an added-up value calculation unit that calculates a sum of the output values of the first sensor and a sum of the output values of the second sensor which are stored in the ring buffer each time the ring buffer is updated, 
 wherein the predetermined storage time and the predetermined time are set to have the same length. 
 
     
     
       12. A method of detecting a percussion position in an electronic percussion instrument including a percussion surface and a first sensor, a second sensor and a third sensor that detect a vibration of percussion on the percussion surface, the method comprising:
 calculating a percussion position in a first direction which is a direction of alignment of the first sensor and the second sensor on the basis of a ratio or difference between an added-up value of output values of the first sensor within a predetermined time after the percussion surface is percussed and an added-up value of output values of the second sensor within the predetermined time; 
 determining presence or absence of the percussion on the percussion surface on the basis of an output value of the third sensor, wherein the third sensor is disposed closer to a center of the percussion surface than to the first sensor and the second sensor; 
 dividing the percussion surface into virtual divided regions being a plurality of divided regions lined up in the first direction between the first sensor and the second sensor; 
 determining which of the plurality of divided regions is percussed on the basis of the percussion position in the first direction; and 
 performing an instruction for generation of musical sounds that vary depending on the plurality of divided regions or an instruction for a change of qualities of the musical sounds on the basis of a determination result of which of the plurality of divided regions is percussed, 
 wherein a starting point of the predetermined time is set to a point in time before a point in time when the presence of the percussion is determined on the percussion surface, and 
 wherein the dividing of the percussion surface into virtual divided regions comprises the following two modes: 
 a first mode in which the divided regions are formed in at least three regions of a first region formed at a center of the percussion surface, a second region formed closer to the first sensor than to the first region, and a third region formed closer to the second sensor than to the first region; and 
 a second mode in which the divided regions are formed in at least two regions of a fourth region formed on the first sensor side with the center of the percussion surface as a boundary and a fifth region formed on the second sensor side with the center of the percussion surface as a boundary, 
 wherein the first mode is set in a case where an interval of the percussion on the percussion surface is equal to or greater than a predetermined value, and the second mode is set in a case where the interval of percussion is less than the predetermined value. 
 
     
     
       13. The method of detecting a percussion position according to  claim 12 , further comprising calculating a coordinate of the percussion position in the first direction on the basis of a magnitude of a ratio or difference between the added-up value of the output values of the first sensor and the added-up value of the output values of the second sensor.